/Engine/Source/Runtime/UMG/Public/Slate/UMGDragDropOp.h
Gets the widget that will serve as the decorator unless overridden. If you do not override, you will have no decorator
virtual [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > GetDefaultDecorator() const